Section 2: Physical Connection; Communication Ports; Standard Usb Interface - Siemens 7SR21 Manual

Section 2: Physical Connection

The relay range provides as standard one 'Front' USB communication interface located on the fascia and one
RS485 located at the 'Rear' with optional Fibre Optic ports (COM3 & COM4), RS485 (COM3) & RS232 (COM3)
also located on the rear.
COMMUNICATIONS MENU
1. Com2-USB: this port is used for IEC60870-5-103 (default setting) communication with the Reydisp
software. An ASCII protocol, the main use of which is to allow firmware to be updated from the front
connection, is also available through this port.
2. Com1-RS485: this port can be used for IEC60870-5-103, MODBUS RTU and DNP 3.0 communications
to a substation SCADA or integrated control system or engineer remote access.
3. Com3/Com4: Optional ports located on the rear of the relay can be used for IEC60870-5-103, MODBUS
RTU and DNP 3.0 communications to a substation SCADA or integrated control system or engineer
remote access.
Any or all ports can be mapped to the IEC60870-5-103, MODBUS RTU or DNP 3.0 protocol at any one time.
Siemens Protection Devices Limited can provide a range of interface devices, please refer to product portfolio
catalogue.
Full details of the interface devices can be found by referring to the website
2.1

Communication ports

2.1.1

Standard USB Interface

The USB communication port is connected using a standard USB cable with a type B connection to the relay and
type A to the PC.
The PC will require a suitable USB driver to be installed; this will be carried out automatically when the Reydisp
software is installed. When the Reydisp software is running with the USB cable connected to a device an
additional connection is shown. Connections to these devices are not shown when they are not connected.
The USB communication interface on the relay is labelled Com 2 and its associated settings are located in the
Data communications menu. To enable communication with Reydisp via the USB port the following setting
changes must be made on the relay via the keys on the relay fascia.
Setting name Range
0 ... 254
Station Address
OFF, IEC60870-5-103,
DNP3.0, MODBUS-RTU,
COM2-USB Protocol
ASCII
©2010 Siemens Protection Devices Limited
Communication settings are only available from the relay front fascia via the
Default
0
IEC60870-5-
103
7SR21 & 7SR22 Data Communications
www.siemens.com/energy
Setting Notes
An address between 1 and 254
1-254
must be given to identify the
relay
Reydisp software uses
IEC60870-5-
IEC60870-5-103 to
103
communicate.
Chapter 4 Page 5 of 15